﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;



class MyCircle
{
    private double radius;

    public MyCircle()
    {
        radius = 0;
    }

    public void setRadius(double r)
    {
        radius = r;
    }

    public double computeArea()
    {
        return Math.PI * Math.Pow(radius, 2);
    }
}

